British light heavyweight Joshua Buatsi made a winning yet underwhelming beginning to his career under fresh promotional backing with a decision win over Parker in the Manchester arena.
The Olympic medal winner's work rate appeared to earn him a judges' verdict in a competitive ten-round fight at the Manchester venue.
But the challenger found success, delivering effective single shots in a match where the approaches didn't complement each other, with frequent clinching marring the action.
Two judges had it 96-94 in favor to Buatsi, with the final judge a 95-95 draw.
"It wasn't my best showing but what do champions do? They succeed," Buatsi stated in the ringside as he was faced negative reactions from the audience.
The Londoner got back to winning after his first professional defeat - an memorable fight with Callum Smith in February - to claim a twentieth professional win.
Some ringside observers believed the challenger, thirty-one, deserved the win but the contender experienced the second defeat of his 28-match career.
The Champion Claims Win in Slow Match
Buatsi's progress has slowed in recent years through promotional disputes and considerable time of inactivity.
Once tipped as the next star of UK boxing, he now is positioned trying to realize his potential - maybe in what appears to be a ultimate opportunity - under new promotional backing.
He began cautiously, with neither fighter ready to take risks in a calculated early stages.
The challenger, whose only previous defeat came at super-middleweight against his former opponent in 2022 after suffering a hand injury during the bout, was competing in only his second appearance at light-heavyweight.
By the fight's midpoint, the underdog had stayed in contention, causing problems for Buatsi, who worked behind a protective stance to narrowly win the cleaner periods.
The spectators' acceptance decreased because of frequent holding, with the challenger falling to the floor various instances during clinches.
Parker closed well, but several stanzas were hard to judge. However, former world champion the boxing analyst - providing analysis for Dazn - had it particularly wide for Parker, awarding Buatsi just one round.
The victor advances, but with the likes of heavy hitter Benavidez, and Russian star Dmitry Bivol leading the category, the journey to titles - judging by this showing - still looks steep.
Ricky Hatton Memorial Fuels Manchester Derby Contest
In the co-main event, Lyndon Arthur beat Rea by split-decision in a terrific local rivalry battle to secure the European light heavyweight title.
The stadium became quiet for a profoundly moving tribute ahead of the contest as ten bells sounded in honor of the city's native Hatton, who passed away at age 46 in recently.
It was the first major televised boxing event in the urban center since Hatton's passing. As the final chime disappeared, the quiet transitioned to a roar of "there's just one Hatton".
The fighting inside the ropes matched the sentiment. Arthur was sent to the canvas by a significant blow squarely on the jaw in the early round, rising shakily to his position on the eight count.
But the red-colored shorts of Arthur soon came forward again. From the other corner, the opponent - in opposing blue - was damaged soon, noticeable damage developing under his orbital area as the pair traded punishing blows.
The challenger, 27, delivered effective strikes but Arthur, 34, fought fire with fire with stinging uppercuts as the pace hardly diminished over twelve rounds.
The victor barely secured the decision with scoring tallies of even score, close margin and wider gap, but the two athletes were relentless and brave, exactly what their hero the legend embodied.
